1. Field of the Invention
The present invention relates to a die package for connection to a substrate (such as a printed circuit board, a flexible printed circuit (FPC), or a flexible flat cable (FFC)) and, more particularly, to a die package for a die (such as a microdisplay die) that connects to a flexible printed circuit.
2. Description of the Related Art
A semiconductor die or chip is an electrical component on which a microcircuit is built. The microcircuits can be interconnected together on the printed circuit board to form larger electronic circuits for use in radios, televisions, compact disc players, and computers, to name just a few. Because the semiconductor die is fragile, it is encased in a semiconductor die package to protect it from the environment. If one were to look inside an electronic device, such as a computer, compact disc player, or cell phone, one would see one or more printed circuit boards on which semiconductor die packages are mounted and electrically interconnected.
The semiconductor die package includes a housing that holds the semiconductor die and conductive leads or pins that extend from the bottom or sides of the housing. The conductive leads are electrically connected to the semiconductor die within the housing. The outside ends of the leads are typically connected to conductive paths on the printed circuit board or plugged into a mating connector on the printed circuit board. This secures the semiconductor die package to the printed circuit board and permits electrical signals to pass between the semiconductor die and other components on the printed circuit board.
Recent breakthroughs in semiconductor technology have led to the development of microdisplays formed on a die. The microdisplay die generates a display, for example, of alphanumeric characters, graphics, or images, in response to electrical signals supplied to the die. The microdisplays may be used in, for example, small appliance displays (e.g., mobile phones and other portable devices), projection televisions, and projectors. The microdisplay dies should be mounted in a die package for protection from the environment. However, conventional package designs are insufficient for housing microdisplay dies. One problem is that microdisplays are sensitive to high temperatures. If a temperature threshold is exceeded the microdisplay die can warp, affecting the image quality of the microdisplay. For example, the temperature threshold of the microdisplay can be exceeded when package leads are soldered to a circuit board using conventional wave soldering techniques. In addition, if the package housing the microdisplay does not permit adequate cooling, the operation of the die itself or other dies within the housing may generate enough heat to cause damage. Moreover, different applications require different mounting and assembly schemes. Conventional solutions are not flexible enough to be convenient for different applications.